Gate for swing-bridges.



Patented Oct. 24. |899.

c. L. PRINDLE.

GATE FOR SWING BRIDGES.

(Apmiction med .my 5, 1599.)

3 Sheets-Sheet l,

(No Model.)

z w e V 1.1 58%./ iM/ C5 o F mi vowels Evans co. Pworomno, wAsnwcfow uc.

No. 635,599. V Patented oct. 24,1899.

c..L. PmNnLE.

GATE FOR SWING BRIDGES.

(Applicmon mea .my 5, i899.) f (No Model.) 3 Sheets-Sheet 2.

l 79am Patented Oct. 24, |899.

C. L. PRINDLE. GATE FUR SWING BRIDGES.

(Application Bled July 5, 1899.)

3'Sheeis-.Sheet 3,

(No Model.)

Ninn *rares ooRYDoN L. PRINDLE, oF EvANsToN, ILLINOIS.

GATE FOR SWING-BRIDGES.

SPECIFICATION forming part of Letters Patent No. 635,589, dated October24, 1899. Application tiled July 5, 1899. Serial No. 722,805. (Nomodel.)

To @ZZ whom, t may concern:

Beit known that I, OoRYDoN L. PRINDLE, a citizen of the United States,residing at Evanston, in the county of Cook and State of Illinois, haveinvented a new and useful Improvement in Gates for Swing-Bridges, ofwhich the following is a specification, reference being had to theaccompanying drawings.

My invention relates more specifically to improvements in theirapplication to swingbridges of the vertically-swinging guards in commonuse at railroad streetecrossings and already incorporated in certainbridge-gate patents and in improvements in the devices for theirautomatic operation, my aim being to provide a safety-gate that shallitself be safe in its operation and practical in actual use and combineas far as possible a maximum lof utility with a minimum of interferencewith the use of the bridge. I attain this obj ect by the mechanismillustrated in the accompanying drawings, in which- Figure l is a frontelevation of the bridgeabutment with the gate attached, the gate beingshown on the right side as open and on the left as closed. Fig. 2 is aplan view of the abutment and gate, the bridge being shown as partlyclosed. Fig. 3 isa plan view of the end of the bridge, a part being cutaway to showin detail the flange peculiar to my invention. Fig. 4 is asection on the line 4 4 in Fig. 2, the gate being in elevation, showingthe parts of the mechanism on one side of the bridge in their relativepositions when the bridge is closed and the gateopen. Fig. 5 partiallyillustrates the various modifications that may be made in thecombination of the gate-guard and actuating-lever; and Fig. 6 is aperspective view of the end of the abutment, showing the application ofthe gate to a bridge crossed by an elevated streetrailway. f

The gate proper in its usual form consists of the main guard O andpedestrian-guard D, attached to the upper surface b of the abutment B,the guards extending horizontally at a suitable elevation across theabutment when the bridge is open and being elevated to a verticalunobstructing position when the bridge is closed. Pivotally supporteduponstandards 7i', attached to the ledge b2 of the abutment, arearranged transverse levers H in approximately parallel lines, the leverusually having a horizontal curvature corresponding to that of theabutment and end of the bridge. The lever has an upper surfaceconsisting of the concave section h3, extending from near the fulcrum h2to the apex h5, and the convex section h4, extending from the apex tothe free end of the lever.

A flange I is projected from and extends usually approximately acrossthe end of the bridge A and at such elevation thereon that a right linecorresponding to its base intersects thelever H at the points hfand hw,Fig. l, when the lever is in the position shown with the bridge open andthe gate closed. The flange usually has a part cut away from its outeredge on the side corresponding to the lever farthest from the edge ofthe abutment, forming the indentation t2, and from the inner edge at theopposite sid e, forming the aperture fi.

A connecting-rod c h is pivotally attached at its upper extremity to thereverse projection o of the main guard at c4 and at its lower extremityto the inner end k7 of the finger h6, projected from the side of thelever at its.

It will be readily seen that in operation as the bridge is being closedfrom either side the flange I impinges and gradually depresses the leverH, which through the medium of the connecting-rod c h simultaneouslyelevates the main guardto the vertical position, the lever and guardgradually gravitating again to their original positions as the lever isreleased by the opening bridge, the gate being thus interposed againbefore the open draw.

The usual pedestrian-guard D protects the footway and in my inventionrotates on the same axis 'c2 as the main guard. The pedestrian-guard iselevated automatically by the main guard by means of the mechanismconsisting of the vibrating lever g', pivoted at one end to thegate-standard at g2, the opposite end connecting pivotally at g5 withthe lower extremities of two radiating arms g3 and g4, which areconnected at their upper extremities with the main and pedestrianguards, respectively, at the pivotal points g8 and gs. It will be seenthat when the main guard is rotated from the horizontal to the verticalposition it carries with it the arm g4, together with thejointly-pivoted arm g3,thereby simultaneously elevating thepedestrianguard. As the pedestrianguard when released returns to thehorizontal position byits own weight and does not require to be forceddown, the connection at gis made to consist of a downwardly-extendingslot cl' and a sliding pivot, which admits of the guard being partiallyraised by hand by pedestrians who are late in passing off the openingbridge or somewhat in advance of the closing bridge. The frequentconvenience of this advantage will be obvious and may sometimes be ofgreat importance. Instead, however, of this automatic mechanism it maysometimes be preferable to provide the pedestrian-guard with aprojecting arm and second'connectingrod corresponding to the equipmentof the main guard, the two connecting-rods jointly engaging the finger,the two guards being thus operated simultaneously bythe lever, as shownin the surface gate in Fig. 6.

' In applying the gate to a bridge crossed by an electric street-railwaywith overhead trolley-wires to avoid contact of the main guard with thetrolley-line the guard is shortened suihciently to admit of its passingunder the wire and extended when in a horizontal ,position to the lengthrequired by means of the trolley-section E. This angular device isattached pivotally to the free end of the main guard at c' and consistsof a horizontal bar c2 and vertical stanchion e". A controlling-bar efis pivoted at one extremity to the stanchion at e4, the other extremitybeing pivoted to the gate-standard F at f'. It will be readily seen thatas the main guard is rotated the controlling-bar ef will hold the bar e2in a constantly horizontal posit-ion, thereby escaping contact with thetrolley-wire. Incidentally the controlling-bar serves as an auxiliaryguard and the stanchion for the usual supporting-pendant.

The main guard is ad justably counterbalanced by the weight c3, whichengages the screw-threaded arm of the guard by means of a threadedperforation, and is readily adjusted as varying atmospheric and otherconditions often require by being revolved into greater or lessproximity to the fulcrum of the guard. The lever H is similarlycounterbalanced by the weight 71u and threaded projection 72,12 and isusually somewhat overcounterbalanced to effect its proper gravitationand with it the main guard when released by the Hange. Then desirable,the mainguard counterbalance may be embraced in the connecting-rod, butnot adjustably, as shown in the elevated gate in Fig. (l. It may alsosometimes be preferable to adjust the guard and lever to counterbalanceeach other.

Usually the main guard consists of two sections c7 and es, Fig. 2,united at the outer ends with the trolley-section when the latter isused, the section c7 having its bearing on the shore side of thesupporting-standard and carrying the counterbalance and the section c8on the river side and engaging the connecting-rod.

The distance of the pivotal point c4 from the fulcrum c2 of the mainguard is proportionate to the fall of the lever at LS, being affectedalso somewhat by the relative direction of oscillation of the twoextremities of the connecting-rod, and the radii of the segments formingthe convex and concave surfaces hL and h3 are governed by the length ofthese surfaces relatively to the fall of the lever, each involving aproblem of geometrical solution, but readily determined by simpleexperiments.

lt is obviously notimperative that the sections hs and '/z* shall berespectively concave and convex in form, but may be right lines forminga vertically-convex contact-surface; but the convex form of the part ofthe lever traversed by the flange in the direction of the fulcrum andconcave form in the opposite direction when the bridge is being closedand the levers depressed and the reverse when the bridge is being openedand the levers released are important, as thereby the same inclinationof the traversed surface to the plane of the flange is maintained at allpoints and a consequent uniformity of speed in the rotation of the guardand of frictional resistance to the'iiange are secured.

The finger 7L, attached to the lever that is actuated by theinner halfof the flange I, will require to be extended downward from the leverbefore being projected to the connecting-rod, as shown by hw, Fig. l, inorder to escape interference with the outerhalf of the flange. It willbe seen that as each leaf of the flange is shortened at the end adjacentto the lever which it acts upon when the bridge is opened in thedirection opposite to either particular lever the flange will begin atonce to release that lever, but when opened in the direction of thelever will not begin to release it until the bridge begins to pass thatside of theabutment with a corresponding action when the bridge is beingclosed, the result obtained being that the lowering or elevating of theguard on either side of the abutment is as nearly as possiblesimultaneous with the opening or closing of the bridge, and consequentlythe greatest eficiency of the gate is secured with the leastinterference with the transit use of the bridge.

It is preferable that the connecting-rod shall be provided' with atension-spring adjusted at any suitable point between its extremities,as shown in the elevated-railway gate in Fig. 6, as thereby theotherwise necessary perfect adjustment between the guard and lever isavoided, sufficient rigidity of the guard is secu red with a yieldingfacility sometimes important, the recoil of the spring starts thedownward gravitation of the guard, and too-sudden impulse of the guardis avoided both in starting and stopping.

Obviously the gate may be locked in the IOO IOS p IIO upright position,and thus rendered inoperative when out of repair, and by making theconnecting-rod readily detachable from the guard the guard may belowered in front of the closed bridge when the bridge is under repairs.

The gate may be as readily applied to an elevated street-railway as to asurface road, as illustrated in Fig. 6. The gate-guard and lever being,one or both, counterbalanced or adjusted to counterbalance each other,and therefore requiring only friction to be overcome in operating them,there is scarcely a limit to the strength that may be given to the gate.The guard at an elevated-railway drawbridge crossing consisting of asingle or trussed bar of iron or steelwith equally strong supports canbe made as strong as the abutment itself and capable of sustaining anypressure or contact that the abutment would withstand. The simplicity ofthe entire mechanism is such that there is little liability to get outof order, and the gate once in position will require little furtherattention. Its value as a guard before an open draw on an elevated roadcan hardly be overestimated, and the sense of security derived therefromby street-car passengers is important even under a system in whichaccidents are supposed to be unlikely to occur.

Obviously the gate may be made to consist of a single guard spanning theentire abutment and actuated by a single lever, and between such simpleconstruction and the mechanism herein described there may be manyvariations, as partially shown in Fig. et, each involving essentialfeatures common to them all. It will be observed that when a singlelever is used the gates, if in pairs on opposite sides of the abutment,will be operated both together, but where two levers are used will beoperated independently of each other. The choice between the differentstyles of construction will be governed by the size and trafficimport-ance of the bridge.

I am aware that many of the features described in clearly explaining myimprovement-s are not original, some of them being common in more orless effective forms to several bridge-gate devices.

What I claim as new, and desire to secure by Letters Patent, is-

l. In a bridge-gate mechanism the independently-movable levers Hprovided with the adjacent concave and convex sections h3 and h4 of thedouble-inclined traversed surface, said levers being pivotally attachedat one extremity to the ledge of the bridge-abutment and engaging atapproximately the opposite extremity the connecting-rods c h, incombination with the independently-movable guards C, saidconnecting-rods c h and the transverse flange I or an equivalentlongitudinal proj ection of the bridge, substantially as and for thepurpose specified.

2. In a bridge-gate mechanism the flange I, having the indentation 2 atoneextremity and the aperture t" at the opposite extremity, incombination with the bridge A and levers H, I-I, substantially as andfor the purpose specified.

3. In a gate of the class described the mechanism consisting of thedevice E, having the horizontal section c2 and vertical section e3, incombination with the controlling-bar c f, the guard C and standard F,substantially as and for the purpose specified.

4. In a gate of the class described the mechanism consisting of thevibrating lever g', and radiating arms g3 and g4, in combination withthe standard F and guards C and D, substantially as and for the purposespecified.

5. In a bridge-gate mechanism the combination with theindependently-movable guards C and connecting-rods c h, of transversevertically-convex vertically-vibrating levers, independently disposedand pivotally mounted approximately at one extremity on the ledge ef theabutment and engaging at approximately the opposite extremity means ofconnecting said levers with said guards, and actuated by a transversehorizontal fiange or equivalent conformation of the end of the bridge,substantially as specified and shown.

6. A bridge-gate mechanism consisting of the combination with vertically-swinging guards, connecting-rods, and a transverse actuating-flange orequivalent longitudinal projection of the bridge, ofindependently-disposed vertically vibrating convex levers, whereby theguards on the opposite sides of the abutment are independently operated,substantially as specied and shown.

7. A bridge-gate mechanism consisting of the combination withverticallyswinging guards, connecting-rods and independentlydisposedvertically-vibrating convex levers, of a transverse actuating-flange orequivalent conformation of the end of the bridge the inner and outersections thereof being suitably shortened at the ends adjacent to thelevers to which they respectively appertain, whereby theindependently-operated guards are actuated approximately simultaneouslywith the transit of the bridge on their respective sides of theabutment, substantially as specified and shown.

CORYD ON L. PRINDLE.

lVitnesses:

ROBERT F. MILNE, FoRDvcE `LA FAYETTE.

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